I'm posting a question for a friend who has a 77 240D automatic with an odd power issue. It has no power at low speeds but does well enough at highway speed. Apparently it isn't getting enough fuel (when he floors it there is no black smoke). He has quite a bit of experience with MB diesels and said earlier models had a butterfly in the intake to regulate airflow. This one apparently is lacking that. He's not sure what to do next - pump timing? valves? Injectors and pump are excellent (starts instantly at sub freezing temps without plugging the block heater in). I thought it might be the transmission vacuum but he said it shifts through all the gears. Any ideas would be appreciated.

Low power compared to what? All 240d's have low power. Is this something that just happened to the car or did the guy buy it and then think it had low power. What are the 0-60mph times?
The 77 300d started in 2nd gear unless you took steps to engage 1st gear. Don't know if the 240d had the same feature but if it does, it definitely gives the appearance of low power.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

He has owned numerous Mercedes diesels including a couple of 240s that he has repaired and is fairly knowledgeable. I don't know the particulars on acceleration time but as he describes it I'm reminded of my 82 300D with numerous vacuum issues. You almost can't get it going forward on an incline without a running start.

This car had been sitting for several years when he bought it to restore it. Linkage was stiff, fluids were old, fuel was bad. He's changed fluids / fuel / filters, run cleaner through the fuel filter, purged the fuel lines, lubricated linkages, etc. It starts almost instantly and runs smoothly at idle, even when cold. Initially it would barely do 40 MPH and crawl up to that speed. Now it cruises comfortably at highway speed when it finally gets there but it's dangerous trying to accelerate to that speed in any kind of traffic.

Low power or no power? Low power is normal I have the 4spd and take off is still slow , think 18 wheeler equivelent. There was a dyno test on this forum that showed 35 rear wheel horespower think garden tractor. The fact that it can get up to 80+ is an incredible feat in itself.

No power check your filters and tank screen , or brakes sticking , do the diesel purge , valves and timing could be off also but if it starts right up in cold temps that would be last on the list. If all things check out the Aneroid capsule can be adjusted for a slight increase in power. If your still not happy then its time for the performance forum.

240D = patience, passengers = more patience best of luck.

__________________


Experience : what you receive 3 seconds after you really needed it !!



86 300SDL 387,000? Motor committed suicide
81 300SD 214,000 "new" 132,000 motor
83 300SD 212,000 parts car
83 300SD 147,000

91 F700 5.9 cummins 5spd eaton 298,000
66 AMC rambler American 2dr auto 108,000
95 Chevy 3/4 ton auto 160,000
03 Toyota 4runner 180,000 wifes

I had the same problem with low power on my 79 240D when I inherited it. I tried everything short of monkeying with the IP internals. This included IP drip timing, valves, chain stretch measurement, etc. Two things made a noticible difference in power. The first was the tank strainer. This was almost completely clogged, and affected the high end power significantly, but not the low end power. The second was the injector nozzles. This made a tremendous difference at the low end and replacing them made all the difference. Two of the original ones were clearly bad when I pop-tested them. Shimming them to the right pop pressure (from 100-105 to 120 bar) made maybe a little bit of difference but not much.
I still think that playing around with the governor adjustments would increase the power, but I am not that ambitious.

He may be knowledgeable. Yet I almost bet he has not dealt with or checked the base supply fuel pressure in the pump. To not do so can hurt performance to some degree is proven. If it is substandard.

Plus once again it may be the long term unproven reason of the number one rod bearing failures on the 616 engines especially. With very low feed pressure I suspect the number one cylinder gets to work harder with the other cylinders laying back a little.

On that suspicious basis alone it should be checked. Have him read the thread in the archives about the relief valve spring completely. Plus if he is smart enough to check this out let us know what pressure he finds. If low the resulant improvements of correcting it are well worth the effort in my opinion. If he corrects this also please post any differences he notices.

He has no Butterfly Valve in the Intake manifold becaues the Governor on the Fuel Injection Pump is a Mechanical one. The older ones needed Vacuum from the Intake Manifold to function properly.

When I first bought my 300D it had similar symptoms. As it turned out my throttle linkage was extremel sloppy and the Throttle Lever on the Fuel Injection Pump was not being moved far enough.
With the Enging cold and not runing have some one get a firm hold of the Throttle Lever down at the Fuel Injection Pump. Have some one work the Pedal and observe what type of slop is in the Linkage.

Next try disconnecting and plugging the Vacuum Shutoff hose at the Vacuum Shutoff. This will prevent any vacuum from reaching the Vacuum Shutoff from a devective Shutoff Valve on the Steering Wheel Lock.

If it has an Automatic Transmission could it be starting in 2nd Gear instead of first?

__________________
84 300D, 82 Volvo 244Gl Diesel

x2 on the throttle linkage.
When I first got my 81, at WOT the fuel valve was barely 1/2 open!
Verrrry slooooowwww!!!

__________________
1981 240D 143k 4 spd manual -SOLD

2004 VW Jetta TDI 5 speed 300k -still driven daily

x3 on the linkage forgot about that one. For checking the linkage on your own you can put a piece of clay , gum ,dab of paint etc. on the linkage stop bolt and see if it touches.

saves on marriage counceling !!

__________________


Experience : what you receive 3 seconds after you really needed it !!



86 300SDL 387,000? Motor committed suicide
81 300SD 214,000 "new" 132,000 motor
83 300SD 212,000 parts car
83 300SD 147,000

91 F700 5.9 cummins 5spd eaton 298,000
66 AMC rambler American 2dr auto 108,000
95 Chevy 3/4 ton auto 160,000
03 Toyota 4runner 180,000 wifes

I once fixed an auto 240 with the same issues, the linkage pivot on the passenger side of the engine block was worn, and the pivot was twisting the wrong way and was only transferring about 1/2 of the linkage movement to the injection pump.

__________________

Great ideal as most pretty girls passing by will not want to respond to a request to observe your linkage for you while they are bent over.

I assumed once again a wrong thing to do that the poster had at least enough experience to check his linkage. They are just too notorious an item to overlook even if your car seems to be okay. Yes more is absolutly always better on a 240d.

LMAO!!

__________________


Experience : what you receive 3 seconds after you really needed it !!



86 300SDL 387,000? Motor committed suicide
81 300SD 214,000 "new" 132,000 motor
83 300SD 212,000 parts car
83 300SD 147,000

91 F700 5.9 cummins 5spd eaton 298,000
66 AMC rambler American 2dr auto 108,000
95 Chevy 3/4 ton auto 160,000
03 Toyota 4runner 180,000 wifes